Expression levels of four genes connected to the ceramide pathway, as measured by qRT-PCR in 15 brain specimens and divided into 3 groups: Alzheimer’s disease (AD, black bars), neuropathologies other than AD (NP, grey bars), and three control (CNTRL) brain samples shown as white bars. Expression of genes was normalized against expression of the PGK1 gene. Expression data for the ASMase, NSMase 2, UGCG, and GALC genes are displayed according to ceramide levels as determined in the particular brain sample (lowest panel). All values are displayed as percentages of the highest value in the group. Bars show SD values for three replicates for real time PCR expression levels values and three measurements for ceramide.